class Screen(object):

    @property

    def width(self):

        return self._width

    @width.setter

    def width(self,width):

        self._width=width

    @property

    def height(self):

        return self._height

    @height.setter

    def height(self,height):

        self._height=height

    @property

    def resolution(self):

        return self._width * self._height